This invention relates to a technology of using information supplied by a large number of sensors connected with the network.
The Internet and other networks have been used in recent years mainly for accessing documents, images, movies, sounds or other stored contents through search engines or previously set links. In other words, the technology of accessing the stored contents has been nearly completed.
On the other hand, a technology of transmitting the current information is streaming technology made up of continuously transmitting images captured by a camera installed at a fixed position (web camera). Lately, sensor network technology of acquiring through a network sensing data acquired from a large number of small wireless sensor nodes is developing (JP 2002-006937 A, JP 2003-319550 A, JP 2004-280411 A, U.S. Patent Application Publication 2004/0093239 Specification, and U.S. Patent Application Publication 2004/0103139 Specification). In recent years, the expectation is growing high for a sensor network system enabling to capture real-world information through sensors and using this information at a remote place through a network. While the present service on the Internet is closed to services on a virtual space, the essential difference of the sensor network from the present Internet is that it is fused with the real world. The possibility of realizing fusion with the real world enables to provide a variety of services dependent on time, location and other situation. The connection of a large variety of objects present in the real world with a network enables to realize traceability and to address to the social needs for securing “safety” in a wide sense and to the needs of “improving efficiency” in inventory control and office work.